Thomas P. Bossert (born March 25, 1975) is an American lawyer and Republican White House staffer, who served as Homeland Security Advisor to President Donald Trump until his resignation on April 10, 2018.
Immediately before, he was a fellow at the Atlantic Council and prior to that he served as Deputy Homeland Security Advisor to President George W. Bush. In that capacity, he co-authored the 2007 National Strategy for Homeland Security. Prior to that, Bossert held positions in the Federal Emergency Management Agency, the Small Business Administration, the Office of the Independent Counsel, and the House of Representatives. He also was appointed as the Director of Infrastructure Protection under Bush, overseeing the security of critical U.S. infrastructure, a post he held for two years.
Bossert was appointed the Senior Director for Preparedness Policy within the Executive Office of the President.